Change arrow indicators the dog often come led. And this is not surprising: the second is much easier and safer first. Simple five-level scheme of the AF voltmeter to the voltage of 0.1—0.6 volts, where the indicators are LEDs, published in the journal “Рипката1ег” (GDR). If the signal fed into socket x2, XS, the voltage exceeds 0.1 V, open transistors V2, V4 and, as a result, the led turns on Q1. With an increase of the signal to 0.2 In open semiconductor triode V6 and the led flashes B2. When the signal voltage reaches about 0.6 V, burn all the LEDs.
LEDs usually have a vertical “column,” much like a thermometer. Increasing the voltage increases the height of a shining pillar, clearly showing the signal level.
To a low-power device, the voltmeter is connected through a matching emitter cascade V1 signal on socket X1.
In the voltmeter instead of overseas semiconductor devices can be applied domestic: transistors КТ306, КТ312 or KT315, diodes Д219, Д220, LEDs АЛ102А — АЛ102Г, choosing the resistance of resistors R3, R5, R7, R9, R11.
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